1. Field of the Invention
The present invention is directed to a method and a system for determining movement of a body organ or therapy region of a patient.
2. Description of the Prior Art
Minimally invasive therapies are increasingly gaining in significance. The goal of such systems is to keep the intervention into the body, and thus the stress on the patient, as slight as possible. Although minimally invasive therapies for location-invariant body regions or organs, for example in the field of neurosurgery or orthopedics, are already being widely employed, the use thereof for, for example, procedures directed to a specified site (for example, a biopsy) at moving organs presents problems. In contrast to manipulation at non-moving body regions, the therapist working in minimally invasive fashion must account for moving therapy regions, for example in the abdominal area, produced, for example, by respiration, blood pulsing, or peristaltic action. In order to exactly align one or more instruments (for example, laparoscope or needles) to a desired target region, for example a metastasis in the liver, and in order also to maintain this alignment during the movement of the organ, a continuous acquisition of the movement of the organ is required.
German PS 198 09 460 discloses a medical aiming device for respiration-adapted puncturing of a target that cannot be displayed with ultrasound using a centesis instrument that is connected to an ultrasound applicator. This aiming device is arranged so as to be longitudinally displaceable at a patient bed of a magnetic resonance apparatus. The centesis instrument can be aligned with respect to the target region on the basis of images of the examination subject registered with an ultrasound applicator as well as with the magnetic resonance apparatus. German OS 197 51 761 and German OS 196 07 023 disclose other systems for movement-adapted assistance in medical procedures.